General
The first question is, what do you want the solar system to accomplish? This helps the designer determine what type of solar system you need. Maybe you want to lower electricity bills. Maybe you want batteries for demand response. Many possibilities. And then the second question is; what is your electrical demand? This will determine the optimal size of the PV array and batteries. Your site may restrict the size of your PV system or there may be more than enough space to accommodate the PV panels. So, start with those three questions; why do I want solar, what is my electrical demand, and how much space do I have on site?
The power that your PV array will produce is a result of the power rating (in Watts) of each PV module multiplied by the number of PV modules. If you have a 550W PV module and you have 60 of them, your total power rating is 33kW. The energy that this system will produce depends on the amount (the hours) of sunlight that the PV array receives. This varies day to day but averages out over the month and year to a determinable number. For example, in the Midwest, we receive an average of ~5 hours of “peak sunlight” each day (lower in the winter and higher in the summer, 2-7 hours generally). So, 33kW multiplied by 5 hours is 165 kWhr/day. But that number has to be discounted by PV system losses. These losses range from 12% to 30%, depending on the age of the system. Typically, designers will use PV system output calculators on the internet, but in general, your system will see -6% due to high PV cell operating temps, 3% dirt on the panels, 4% inverter loss, 3% voltage drop over wires, 2% PV module degradation, 2% orientation/tilt angle mismatch = 20% So, typical output from a 33kW system will be ~132 kWhr / day (165 x 0.8). this number can be improved with single axis tracking but this adds complication and cost to the system
Using the example above, a commercial PV system installed cost (generally) ranges from $2.50 to $4.50 per watt. So, if we use $3.50 installed cost and we have a 33kW system, we have a total installed cost of $115,500. State and Federal incentives can lower this cost by ~40% ($69,300). If your local price for electricity is $0.18/kWhr, your payback would be ~8 years.
Batteries were a part of every solar system before grid-tie inverters came along in 2001. And now we are seeing a renaissance in battery installations because of new technology, better pricing, new incentives and greater acceptance of exporting battery power on to the grid. Battery ROI is harder to quantify but is irreplaceable when it comes to emergency backup or active demand response at commercial sites. Customers can add batteries to any Solar Mounts PV system, although we do not install batteries. We can create the pad where the batteries will be installed on site, close to the PV array
No difference! “Solar panel” is the most common slang for a single unit. A “PV panel” is better. It distinguishes between a solar thermal panel and a solar electric panel. PV stands for photovoltaic (electricity from light). The best, most proper name for these devices is a photovoltaic module, or “PV module”. Note, it is proper to use “PV panel” when describing a small group of PV modules shaped into a square or rectangle. A “PV array” is the complete group of PV modules/panels on site, all connected to a particular PV system inverter.
The difference is in the mounting structure. Solar Mounts only manufactures fixed PV array structures. The designers determine the best tilt angle for the site, and the PV array remains fixed at that angle. Single axis tracking structures will change their tilt angle throughout the day. Facing east in the morning, they will move to face west at sunset and then flip back in the morning to meet the eastern rising sun. This mounting strategy can add 10-15% to the PV system’s daily kWhr output but these tracking systems cost more and require more maintenance.
A solar inverter is a device that can accept a range of dc voltages and invert that dc power to ac power. The inverter is typically 90-98% efficient in this process. There is usually a heat sink and a fan to help cool the inverter during operation. There is a “connection interface” on the bottom of the inverter where the installer connects dc, ac, battery and monitoring wires. Normally, there is an LCD display to tell the operator how the inverter is functioning. Typically, the inverter goes into “sleep mode” overnight and wakes up when the PV array starts producing voltage in the morning. Common commercial inverters range in size from 20 kW to 4 MW.
It is common to see that the mounting structure is installed first, then the PV modules are installed on the mounting structure. At about this time, the electrical team (electrician) comes in to install the inverter and make the connections to the ac breaker box. At this point, the distance between the PV array and the inverter (and maybe the batteries) is established. Now the PV modules are connected in groups, maybe two per group for a 24- or 48-volt system and maybe 6-12 per group if you are using an inverter that accepts higher dc voltages. Then the groups are wired to a fused dc combiner box and a single output from the combiner box is routed to the inverter. There are dc and ac switches to install. There is monitoring to install. But in general, the mounting structure is first. In the case of Solar Mounts, we start with the foundations. Then we erect the steel and then mount the solar modules on the structure. Electrical teams wire the PV module groups (i.e. “strings”) to combiner boxes and the combiner box outputs are routed to the inverter(s).
Solar carport lighting can be used both for safety and aesthetics. Fixtures use long-lasting LEDs and canopy lights can be sourced from manufacturers around the world, including the good ol’ United States. Solar carport lighting is normally installed after conducting a photometric study to determine the height and spread of light from each fixture. The fixtures are then installed to provide complete coverage of the parking spaces (and sometimes the ingress/egress parking aisles). Typically, carport owners do not want the light to spread beyond the carport space. Fixtures can be equipped with photometric sensors so that the lights come on at dusk and turn off at dawn. Many fixtures have the ability to adjust the light color. Solar Mounts offers a wildlife friendly canopy light that emits light at 590 nm, which is safe for turtles and other nocturnal creatures. At other sites you may add a motion sensor so that the lights come on when a car or person moves under the canopy. Many fixtures offer dimming, for when there is no movement under the canopy. Proper lighting can provide a sense of security under the canopy at night. Lighting can provide a pleasant aesthetic to the parking structure. To make things convenient during setup, owner/operators are normally given a remote to set up, adjust and control their lighting fixtures.
All structural steel and construction materials used in Solar Mounts products are proudly sourced and manufactured in the United States. Every step of the steel production process—including forming, rolling, drawing, finishing, fabrication, and coating—is completed at ISO 9001-certified facilities located in Michigan and other Midwest regions. For documentation purposes, contractors can download and print the Solar Mounts Application Note on AIS (American Iron and Steel) Compliance.
